1. Field of the Invention
The present invention relates generally to a cellular communication system and, more particularly, to a method and apparatus for transmitting downlink control information in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system in which radio resources are allocated in units of Resource Blocks (RBs).
2. Description of the Related Art
With the advance of mobile communication technologies, mobile communication systems have evolved to support high speed data communication services as well as the standard voice communication services. However, there is still a need for a more sophisticated mobile communication system that mitigates resource shortages and meets the varying high-speed service requirements of subscribers.
Typically, in a cellular communication system, a base station sends scheduling information about data to be transmitted to a User Equipment (UE) with Downlink Control Information (DCI). There are various DCI formats defined for indicating whether the information is uplink scheduling information or downlink scheduling information, whether the information is compact DCI, or whether the information is for multiple antenna-based spatial multiplexing, and whether the information is power control DCI.
Recently, a great deal of research is being conducted to improve usage efficiency of limited radio resources, which is current being considered as a possible approach for reducing DCI overhead.